The term is a slang word that originated in the gay community and comes from the equestrian term bareback, which refers to the practice of riding a horse without a saddle. A few extremely flexible males can reach and stimulate their penis with their tongue or lips, and so perform autofellatio. The name of the practice, when it is done in a repeated in-and-out motion, is derived from its passing resemblance to the dipping of a tea bag into a cup of hot water as a method of brewing tea. In pornography, depictions of lesbian sex form a popular subgenre, directed toward a male heterosexual and female homosexual audience. Enema pornography involves adults given enemas to others, often fake. Pornography is generally classified as either softcore or hardcore pornography. Arousal may be triggered by seeing the body movements or facial expressions of that person. The term lesbian is also used with regard to sexual identity or sexual behavior, regardless of sexual orientation, or as an adjective to characterize or horny milfs associate nouns with female homosexuality or same-sex attraction. By Japanese law, the genitals of anime hentai actors and actresses must be censored and up the mid-1990 so was the depiction of pubic hair. Entacle erotica describes a type of pornography most commonly found in Japan which integrates traditional pornography with elements of bestiality and a fantasy, horror, or science-fiction theme. Originating in Japan in the 1980s, the genre subsequently spread to North America and Europe, and crossed gay fuck over into gay pornography. Depictions of male and female masturbation are common in pornography, including gay pornography. For uncircumcised males, stimulation of the penis in this way comes from the pumping of the foreskin, in which the foreskin is held and slid up and down over the glans, which depending on foreskin length, is completely or partially covered and then uncovered in a rapid motion. As a result, little in history was documented to give an accurate description of how female homosexuality is expressed.